1. Field of the Invention
This invention relates to a pesticidal composition comprising a specific organophosphorus compound and a pyrethroid.
2. Description of the Prior Art
It is well known that certain cyclopropane carboxylic acid derivatives are an important class of pesticides called "pyrethroids". These natural and synthetic pyrethroids have been of considerable interest because of their quick knock-down activity, low persistence as toxic residues and their low mammalian toxicity. Certain derivatives of phenylacetic acids have also been found to have properties of the pyrethroid type. While such compounds are desirable pesticides, because of their relatively complex chemical structures they tend to be difficult or expensive to manufacture.
Applicants have found that certain combinations of synthetic pyrethroids with other known pesticides as hereinafter described possess synergistic activity with respect to dipterous and to ticks, that is to say the activity of the combination of two pesticides produces more than an additive pesticidal effect.